For what it is worth I too discovered my new 05 Sport V8 makes the same noise (with 300 miles on it). It was about 40* today and yes, frustrating. Hoping somebody finds a tsb on it soon.

Just a quick update - I brought mine in for the 5k service and explained the harmonic vibration problem from 70-75 mph. The dealer told me they never heard of it. They said that the only thing they found vibrating was my ski rack. I told them I had the vibration for months before putting the ski rack on. They said they rebalanced the tires. I told them it wasn't a tire problem. THESE PEOPLE DON'T FREAKIN' LISTEN TO ANYTHING YOU TELL THEM!!!:awais:

I have a feeling that they aren't even working on a fix for this thing. It's somewhat depressing. Does anyone have any clue what the problem is? Has anyone taken their car to anyone other than a Toyota dealer? I'm thinking of taking it to a non-dealer and letting them have a crack at it. Then, if they can fix it, maybe I'll go back to Toyota and try to make them pay for it.

Anyone else have any updates???

Kenny g...

Based on the parts in the TSB for the Lexus version, Toyota is thinking that the noise is caused by a interaction between a harmonic vibration in the front axle and engine RPM. The Lexus TSB was to replace a vibration dampener that attaches the front axle to the frame.

Some simple tests by myself and few others, have noted that the harmonic occurs at a certain RPM/speed range, which is 1,800 to 2,200 RPM around 73-80 MPH. When dropping the engine out of overdrive, or accelerating hard through that speed range, the noise isn't noticed.

So basically, it seems like toyota knows about the problem and it's causes, but doesn't feel that it's widespread enough to repair it on the 4R. I don't know for fact, but I thought I read that the Lexus TSB didn't solve the problem 100 percent either.

I'm just living with it for now, and hoping that Toyota addresses it eventually. Heck it took them over three years to address the sludging problem with the Camrys, and that was a much more serious problem.

--Mike

Take it from someone who has gone to two dealers, written to and phoned Toyota Customer Service, don't waste your time. The best thing to do is open a case with Toyota Customer Service, that way they have a number of how many are complaining. Learn to live with it unfortunately. Good luck.

Thought I would also speak up - as most of the folks on this thread have the V8's with AWD.

I get the same harmonic vibration when I engage my 4WD and reach speeds of 65 to 75 mph. However, I've determined that the vibration only occurs when the drvietrain is under a strain, such as accelerating the engine. If you are just cruising along and not asking anything of the engine the driveline does not vibrate at all. Also, if you drop a gear, thus raising the RPM's, the vibration goes away as well.

My background is in mechanical engineering and what I've concluded is that it is indeed a harmonic vibration. The torsional stiffness and rotating inertial mass must yield a natural resonance frequency equal to the rotating speed of the driveline at this vehicle's speed. It seems like a huge oversight if you ask me, as when we design high speed rotating equipment here the very first thing we look at are the system's critical speeds. Adding a harmonic dampner, in the case of the Lexus fix, is questionable. Without knowing the details, I'd question the longevity of this fix and whether the harmonic vibration levels are merely hidden from the steering wheel yet still could cause premature wear on the drivetrain system.

Fortunately, I only engage the 4WD when it's slippery (rain/snow) out, and typically don't drive that fast because the conditions are poor - so I'm not too worried about the wear. That said, those with AWD systems that do a lot of highway driving should be raising the issue with Toyota as it may present premature wear on certain drivetrain components.

thanks for the input. yeah, i have full time 4WD. I raised the issue of premature wear with them and they told me there isn't an issue, and they said the powertrain warranty is much higher then the regular warranty. I told them that I plan on keeping this truck for 10 years if I can, which will put it WAY past that. If they provided me with data on vehicles/drive trains that had been put through exhaustive/prolonged testing then I would feel more comfortable. But they just expect me to take their word.

I am looking to replace my V6 SE 4Runner with the V8 2005 SE as I can't stand the constant knocking on my V6 which has also been discussed on this board. My MPG seems to be going lower and lower the longer I drive it. Is this "harmonic vibration" something on all 2005 V8's? What should I be looking for or listening for when test driving a new one?

I had the vibration in my V8 AWD when it was new. Just at about 60+ to 70+/- MPH when going up hill.

I have noticed that since I have had to really get on it a couple of times from a stop I don't have the vibration anymore.

ScotAW:

You seem to be the first V6 owner that is reporting the same problem that the GX470 and some of us V8 AWD owners are experiencing. In addition to the harmonics at 65-75, do you also experience the "1700 RPM vibration" at lower speed in lower gears?

I agree with your concern that the Lexus TSB just hides a problem that may cause premature wear and failure. Of course, Toyota corporate tells me, "trust us, it won't cause undue wear." Toyota also makes contradictory statements about the problem. On the one hand, they say it is "characterstic of the vehicle." On the other hand, they say it happens to too few 4Runners for Toyota to bother to fix it.

If I could switch off the AWD, I would be much less concerned.

Seems like Lexus here and Toyota in Aus have fixes for it, but Toyota here is not interested.

http://www.lcool.org/technical/120_s...tion/90hz.html

I read on a LX470 forum that they have some that had harmonic problems. I guess all LX's have weights at different points on the vehicle that regulate the harmonic's in the drivetrain. I'm not concerned, but I don't have a harmonic problem Hope they find a fix for you guys with the problem.

I just gotta say that I looked for the problem on my '05 SE V-8 4X4. I found it when I was looking for it. It seems to have gone away now at 5K miles.

With all the hystronics everyone has about this "Problem Indicator" I have not seen anyone have a mechanical failure from whatever is causing it. No one is reporting that the problem gets worse with mileage. Nothing ever breaks or wears out from it happening.

I think I have made my best vehicle purchase ever with this vehicle. Even with the "vibration"!!!


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Are the parts mentioned there the same/similar to those on the 4Runner?

The prado/4runner/GX share the same driveline, so th parts will fit on all of them.

Sorry about the old thread........but my V6 does the same thing whether it is in 2hi or 4hi. I guess this is more than just a V8 problem.